The present invention relates generally to automotive safety belt retractor assemblies and, more particularly, to such a retractor assembly having an improved comfort mechanism and a method of operating and cancelling the same.
Virtually all motor vehicles are now equipped with safety belt restraint systems for physically restraining the seat occupants when the vehicle is subjected to a high rate of deceleration which may occur, for example, during a motor vehicle collision. Most safety belt restraint systems include one or more retractor assemblies which function to selectively permit and inhibit the withdrawal of belt webbing therefrom. In addition, some retractor assemblies also include one or more comfort features for providing the seat occupant with enhanced seating comfort. For example, an emergency locking retractor ("ELR") permits belt webbing to be controllably withdrawn from the retractor assembly during normal vehicle operating conditions for providing increased freedom of movement for the vehicle occupants. However, the "ELR" prevents the withdrawal of belt webbing from the retractor assembly when the vehicle is subjected to deceleration forces above a predetermined maximum level, thereby restraining the vehicle occupant.
As an additional comfort feature, some safety belt retractor assemblies are also equipped with a tension relieving device or so-called "comfort" mechanism. In general, comfort mechanisms are adapted to prevent the retractor assembly from exerting a retractive force on the belt webbing which tends to be uncomfortable and annoying to the seat occupants. Conventional comfort mechanisms are typically actuated in response to the magnitude and direction of belt movement for introducing a limited amount of "slack" to the belt webbing. Thereafter, the comfort mechanism can be "cancelled" for removing the "slack" by withdrawing a predetermined length of the belt webbing from the retractor assembly. Upon cancellation of the slack, the retractor assembly exerts the retractive force on the belt webbing for returning it to a "taut" position against the seat occupant. Moreover, governmental regulations now require that the tension relief feature of any comfort mechanism be automatically cancelled in response to the occurrence of specific conditions such as, for example, opening of the vehicle door.
Accordingly, the present invention is directed to an improved comfort mechanism for use in safety belt retractor assemblies. Actuation of the comfort mechanism for setting the desired amount of belt "slack" requires a conscious "intentional" and "deliberate" act on the part of the seat occupant. As such, the safety belt retractor assembly of the present invention will not provide tension relief until the comfort mechanism is deliberately actuated by an intentional act of the vehicle occupant. As a related object, the present invention is directed to a method for actuating and cancelling the tension relief feature of the improved comfort mechanism.
A further object of the present invention is to provide means for automatically cancelling the tension relief feature of the improved comfort mechanism in response to the occurrence of a predetermined condition. To this end, the comfort mechanism of the present invention includes a solenoid-actuated release mechanism operable for automatically cancelling the tension relief in response to an electrical signal indicative of the predetermined condition.
The improved comfort mechanism of the present invention includes a locking member, a driven member and a movable actuation member located intermediate to the locking member and the driven member. With the comfort mechanism in a "non-actuated" mode, the locking member is disengaged from the driven member for prohibiting tension relief (i.e., "slack") in the safety belt. When it is desired to place the comfort mechanism in its "acutated" mode, the safety belt is extracted from the retractor assembly to its fully extended position. Thereafter, the seat occupant must intentionally and deliberately "tug" or "snap" the safety belt for causing the actuation member to move to a position wherein the locking member is permitted to engage the driven member for providing the desired tension relief. A release mechanism is provided for returning the comfort mechanism to its "non-actuated" mode for automatically cancelling the tension relief feature under certain specific conditions.
Additional benefits and advantages of the present invention will become apparent to those skilled in the art from studying the written description and the appended claims, taken in conjunction with the accompanying drawings.